Electricity distribution companies (utilities) are becoming increasingly challenged to maintain a reliable electricity supply. Historically, electricity has been generated with large, megawatt level powerplants. FIG. 1 illustrates an electric grid including a centralized electrical power generation subsystem 100 including a large-scale power generation system 102, a transmission system 104, and a distribution system 106. The large-scale power generation system may use hydro, fossil fuel, and nuclear energy to generate the electrical energy. The large-scale generation system 102, as is typical, delivers three phase power to the transmission system 104. The transmission system 104 consists of thousands of miles of three-phase transmission lines connected to the distribution system 106, which includes a network of thousands of distribution points delivering electrical power to industrial, commercial, and residential loads. The electrical grid 100 comprises a large number of large scale power generation systems 102, connected by the transmission system 104, delivering electricity to many consumers.
Generation and deployment of power is managed by Independent System Operators (ISOs). ISOs are tasked with ensuring that sufficient capacity is available to meet the minute-to-minute daily demand and that this energy is provided at lowest cost. To ensure supply reliability, enough ‘spinning reserve’ from gas-fired peaker plants is kept on tap to satisfy peak demand and, to recover from any large generator outage, at considerable cost.
Distributed storage and generation of renewable energy are the primary technologies currently being touted to ensure a safe and reliable supply of electrical energy for the future. Large-scale solar arrays and wind farms provide distributed electrical power generation. Roof-top solar arrays generate electrical power at thousands of residential and commercial locations.
Wind and solar, however, do not consistently generate electrical energy. Solar energy generation may peak at noon and provide no power at night. Distribution companies are being entrusted with the daunting task of integrating renewables into the electrical power system 100. The integration of renewables, the requirement to provide net-metering, and the solution to problems associated with supplying a diverse load has become increasingly challenging.